Semiconductor device and method of manufacturing semiconductor device

Abstract

The semiconductor device includes a first transistor including a first impurity layer containing boron or phosphorus, a first epitaxial layer formed above the first impurity layer, a first gate electrode formed above the first epitaxial layer with a first gate insulating film formed therebetween and first source/drain regions, and a second transistor including a second impurity layer containing boron and carbon, or arsenic or antimony, a second epitaxial layer formed above the second impurity layer, a second gate electrode formed above the second epitaxial layer with a second gate insulating film thinner than the first gate insulating film formed therebetween, and second source/drain regions.

1. A method of manufacturing a semiconductor device comprising:
 ion implanting a first impurity of a first conduction type in a first region of a semiconductor substrate by using a first mask exposing the first region; 
 ion implanting, in a second region of the semiconductor substrate by using a second mask exposing the second region, a second impurity of the first conduction type, whose diffusion constant is smaller than the first impurity or the first impurity and a third impurity which suppresses a diffusion of the first impurity; 
 activating the first impurity and the second impurity to form a first impurity layer in the first region and a second impurity layer in the second region; 
 epitaxially growing a semiconductor layer above the semiconductor substrate with the first impurity layer and the second impurity layer formed in; 
 forming a first gate insulating film above the semiconductor layer in the first region and the second region; 
 removing the first gate insulating film in the second region by using a third mask exposing the second region; 
 forming a second gate insulating film thinner than the first gate insulating film above the semiconductor layer in the second region; and 
 forming a first gate electrode above the first gate insulating film and a second gate electrode above the second gate insulating film. 
 
     
     
       2. The method of manufacturing a semiconductor device according to  claim 1 , wherein
 the first impurity is boron, and 
 the third impurity is carbon. 
 
     
     
       3. The method of manufacturing a semiconductor device according to  claim 2 , wherein
 before the first impurity and the third impurity are implanted, a fourth impurity is ion implanted in the second region for amorphizing a surface region of the semiconductor substrate. 
 
     
     
       4. The method of manufacturing a semiconductor device according to  claim 3 , wherein
 the fourth impurity is germanium. 
 
     
     
       5. The method of manufacturing a semiconductor device according to  claim 1 , wherein
 the first impurity is phosphorus, and 
 the second impurity is arsenic or antimony. 
 
     
     
       6. The method of manufacturing a semiconductor device according to  claim 1 , further comprising forming the semiconductor layer:
 forming a device isolation insulating film in the semiconductor substrate with the semiconductor layer formed on. 
 
     
     
       7. The method of manufacturing a semiconductor device according to  claim 1 , wherein
 in forming the first gate insulating film, the first gate insulating film is formed after etching by using a fourth mask exposing the first region to expose a surface of the semiconductor layer in the first region. 
 
     
     
       8. A method of manufacturing a semiconductor device comprising:
 ion implanting a first impurity in a first region of a semiconductor substrate by using a first mask exposing the first region; 
 ion implanting a second impurity of the same conduction type as the first impurity in a second region of the semiconductor substrate by using a second mask exposing the second region; 
 ion implanting a third impurity of a conduction type opposite to the first impurity in a third region of the semiconductor substrate by using a third mask exposing the third region; 
 ion implanting a fourth impurity of a conduction type opposite to the first impurity in a fourth region of the semiconductor substrate by using a fourth mask exposing the fourth region; 
 activating the first impurity, the second impurity, the third impurity and the fourth impurity to form a first impurity layer in the first region, a second impurity layer in the second region, a third impurity layer in the third region and a fourth impurity layer in the fourth region; 
 epitaxially growing a semiconductor layer above the semiconductor substrate with the first impurity layer, the second impurity layer, the third impurity layer and the fourth impurity layer formed in; 
 forming a first gate insulating film above the semiconductor layer in the first region, the second region, the third region and the fourth region; 
 removing the first gate insulating film in the second region and the fourth region by using a fifth mask exposing the second region and the fourth region; 
 forming a second gate insulating film thinner than the first gate insulating film above the semiconductor layer in the second region and the fourth region; 
 forming a first gate electrode above the first gate insulating film in the first region, a second gate electrode above the second gate insulating film in the second region, a third gate electrode above the first gate insulating film in the third region and the fourth gate electrode above the second gate insulating film in the fourth region. 
 
     
     
       9. The method of manufacturing a semiconductor device according to  claim 8 , wherein
 the first impurity is boron, 
 the second impurity contains boron and carbon, 
 the third impurity is phosphorus, and 
 the fourth impurity is arsenic or antimony. 
 
     
     
       10. The method of manufacturing a semiconductor device according to  claim 8 , wherein
 in implanting the second impurity, before the second impurity is implanted, a fifth impurity is ion implanted in the second region for amorphizing a surface region of the semiconductor substrate. 
 
     
     
       11. The method of manufacturing a semiconductor device according to  claim 10 , wherein
 the fifth impurity is germanium. 
 
     
     
       12. The method of manufacturing a semiconductor device according to  claim 8 , further comprising after forming the semiconductor layer:
 forming a device isolation insulating film in the semiconductor substrate with the semiconductor layer formed on. 
 
     
     
       13. The method of manufacturing a semiconductor device according to  claim 8 , wherein
 in forming the first gate insulating film, the first gate insulating film is formed after etching by using a sixth mask exposing the first region and the third region to expose a surface of the semiconductor layer in the first region and the third region. 
 
     
     
       14. A semiconductor device comprising:
 a first transistor including:
 a first impurity layer formed in a first region of a semiconductor substrate and containing boron; 
 a first epitaxial semiconductor layer formed above the first impurity layer; 
 a first gate insulating film formed above the first epitaxial semiconductor layer; 
 a first gate electrode formed above the first gate insulation film; and 
 first source/drain regions formed in the first epitaxial semiconductor layer and the semiconductor substrate in the first region; 
 
 a second transistor including:
 a second impurity layer formed in a second region of the semiconductor substrate and containing boron and carbon; 
 a second epitaxial semiconductor layer formed above the second impurity layer; 
 a second gate insulating film formed above the second epitaxial semiconductor layer and being thinner than the first gate insulating film; 
 a second gate electrode formed above the second gate insulating film; and 
 second source/drain regions formed in the second epitaxial semiconductor layer and the semiconductor substrate in the second region; 
 
 a third transistor including:
 a third impurity layer formed in a third region of the semiconductor substrate and containing phosphorus; 
 a third epitaxial semiconductor layer formed above the third impurity layer; 
 a third gate insulating film formed above the third epitaxial semiconductor layer and having a film thickness equal to a film thickness of the first gate insulating film; 
 a third gate electrode formed above the third gate insulating film; and 
 third source/drain regions formed in the third epitaxial semiconductor layer and the semiconductor substrate in the third region; and 
 
 a fourth transistor including:
 a fourth impurity layer formed in a fourth region of the semiconductor substrate and containing arsenic or antimony; 
 a fourth epitaxial semiconductor layer formed above the fourth impurity layer; 
 a fourth gate insulating film formed above the fourth epitaxial semiconductor layer and having a film thickness equal to a film thickness of the second gate insulating film; 
 a fourth gate electrode formed above the fourth gate insulating film; and 
 fourth source/drain regions formed in the fourth epitaxial semiconductor layer and the semiconductor substrate in the fourth region. 
 
 
     
     
       15. The semiconductor device according to  claim 14 , wherein
 the second impurity layer contains germanium.